Contributing Editors Emmanuel Fritsch, University of Nantes, CNRS, Team 6502, Institut des Matériaux Jean Rouxel (IMN), Nantes, France (fritsch@cnrs- imn.fr) Gagan Choudhary, Gem Testing Laboratory, Jaipur, India ([email protected]) Christopher M. Breeding, GIA, Carlsbad ([email protected])

convention center. Though sales have slowed, col- TUCSON 2016 ored stones have gradually gained momentum among jew- elry customers, and designers are responding in kind. Although the overall market share for colored stones is still For decades, buyers and sellers from every aspect of the gem small compared to the diamond sector, efforts to promote and jewelry industry have flocked to the gem fair in Tucson, them have had very positive results. a town in the heart of Arizona’s Sonoran Desert that is rich in cultural and natural heritage. The annual shows are More Serious Buyers. After the surge of foot traffic on the widely considered a forecast for the rest of the year. While opening day, attendance remained stable at the shows for the shows of the past few years have reflected a sluggish in- the rest of the week (figure 1). Vendors saw fewer Chinese dustry, the atmosphere in 2016 was dramatically different, buyers than in 2014, though Josh Saltzman of Nomad’s Co. with an increase in both attendance and business. The 34th (New York) indicated that those who came were serious AGTA GemFair saw record pre-registration numbers, and buyers picking up high-quality goods. Gaurav Shah from more than 300 exhibitors greeted a full house of buyers on Real Gems Inc. (New York) confirmed that his company has the opening day. Gabrièl Mattice of Pala International (Fall- seen greater demand for in mainland China since brook, California) said that sales were very strong this year, 2007, a market that slowed in 2015. He said that the Chi- even on the first day of the show. The energized interaction nese are more cautious and specific in their purchases, and between exhibitors and buyers was evident throughout the he predicted an upswing in Chinese buying activity in the near future. Joseph Nakamura of Shogun (White Plains, New York) said that 95% of his customers were from Figure 1. Tucson’s GJX show saw considerable traffic the United States, while Gabrièl Mattice also saw many Eu- this year, including a higher number of American ropeans on the floor, especially French buyers. Many new buyers. Photo by Andrew Lucas. buyers attended, possibly due to the stabilized prices and heightened interest in colored stones (figure 2). Mr. Shah ob- served three categories of clients in Tucson: buyers from tel- evision and Internet companies, retailers, and designers. David Bindra of B&B Fine Gems (Los Angeles) noted that the number of transactions relative to the attendance was much higher than in previous years. He felt that this year’s AGTA show was much better than the September 2015 Hong Kong and Gem Fair, where many sellers felt the slowdown of the mainland Chinese market.

Editors’ note: Interested contributors should send information and illustra- tions to Stuart Overlin at [email protected] or GIA, The Robert Mouawad Campus, 5345 Armada Drive, Carlsbad, CA 92008.

GEMS & GEMOLOGY, VOL. 52, NO. 1, pp. 82–102.

© 2016 Gemological Institute of America

82 GEM NEWS INTERNATIONAL GEMS & GEMOLOGY SPRING 2016 Figure 2. A customer examines some calibrated Figure 4. Morganite attracted many American buyers at the Real Gems booth in the AGTA this year. Photo by Andrew Lucas. show. Photo by Tao Hsu.

Calibrated Goods. Though high-end colored gems con- Classics. No single stone stole the show this year. Some tinue to set auction records, the market for these stones re- relatively new varieties were available, but their potential mains slow. As a result, the colored stone trade still mainly is still hard to evaluate. Some people asked about the color- consists of goods in standard calibrated sizes rather than change pink that has recently been covered custom-cut material (figure 3). Many cutting factories are by multiple trade magazines, including the Winter 2015 able to provide a greater selection of sizes that fit their G&G. Ms. Mattice said it will take time to educate people clients’ requirements. This especially benefits the jewelry about this stone, and it is not easy to predict the market manufacturers in China and India, as setting calibrated potential. Mr. Bardiya informed us that morganite (figure gems is the bulk of their workload. Thus, mid-priced col- 4), aquamarine, and blue were popular among RMC’s ored goods were the overall best sellers in Tucson. Nirmal American clients. According to Joseph Nakamura, white Bardiya of RMC Gems (Bangkok) informed us that cali- still dominate, while other colors come and go with brated goods of various millimeter sizes are best sellers in different fashion trends. According to multiple dealers, the American market, while Arthur Groom Jr. of Eternity Paraíba is still in high demand (figure 5). Natural Emerald (Ridgewood, New Jersey) noted that Even so, the “big three” of , , and emerald Afghan emerald melee is one of his biggest sellers. Guarav still dominate the market and fetch higher prices, which Shah reported that the most popular calibrated cuts are was reflected in this year’s shows. Corundum is still the oval, emerald, and pear shapes; these goods generally range most popular material in the high-end sector. David Bindra from $200–$2,000 per . and Gabrièl Mattice both said that sold very well,

Figure 5. According to many exhibitors, Paraíba tour- Figure 3. Assorted goods in calibrated sizes sold very maline remained one of the shows’ best sellers. Photo well at the shows. Photo by Tao Hsu. by Andrew Lucas.

GEM NEWS INTERNATIONAL GEMS & GEMOLOGY SPRING 2016 83 Figure 6. Colored stone jewelry is becoming in- creasingly popular among consumers, as designers such as Paula Crevoshay use colors in more creative ways. Photo by Tao Hsu.

and Mr. Bindra thinks that blue and green material will be encouraged by the renewed momentum of the American especially strong this year, though yellow sapphires drew market, even though high-end buyers were still cautious. more interest than at previous shows. Pink and pastel-col- Relatively stable prices also contributed to increased sales, ored sapphires also attracted many buyers, perhaps because although the price of sapphire, ruby, and emerald remained they evoke rose and serenity blue, Pantone’s colors high. With the positive forecast from Tucson, the trade is of the year for 2016. expecting a prosperous 2016. We thank the many exhibitors who provided insight, Interest and Demand for Color. As one of the best plat- photos, and materials. forms to trade and promote colored , the Tucson Tao Hsu and Andrew Lucas shows provide buyers with the finest goods sourced from GIA, Carlsbad all over the world. Some one-of-a-kind stones debut here, such as the 332.24 ct Imperial topaz carving seen on pp. Afghan emerald, Tajik ruby, and clarity-enhanced tourma- 88–89. Spectacular stones such as these usually attract im- line. Eternity Natural Emerald (Ridgewood, New Jersey) mediate attention. exhibited a number of fascinating stones at the AGTA Mr. Bindra tied the increase in sales to a growing aware- show. The emerald melee from Afghanistan (figure 8) im- ness of colored stones. Once-daunted consumers are be- mediately caught our attention. One of the authors was coming more knowledgeable about different varieties and present in Afghanistan when Eternity’s Arthur Groom ex- are better prepared before they purchase. This interest in learning was reflected at the AGTA GemFair seminars, which saw a 30% increase in attendance. Figure 7. Some pieces offered excellent options for de- Greater appreciation for colored stones motivates de- signers who wish to create a unique look. Photo by signers and retailers to source more of them (figure 6). Mr. Tao Hsu. Shah did business with more designers than in previous shows. The authors themselves saw materials in more unique cuts that seemed intended to capture the designers’ imagination (figure 7). Mr. Shah said that even though Real Gems is a wholesaler, the company does not have a mini- mum order requirement for any buyers. This is very help- ful for many designers, especially the young ones. This exhibitor feels that it is worthwhile to do business with people who are willing to work with and promote colored stones in their own work.

Summary. Based on their own observations, the authors were not surprised to hear vendors say that this was one of the strongest Tucson shows in recent history. People were

84 GEM NEWS INTERNATIONAL GEMS & GEMOLOGY SPRING 2016 Figure 8. Left: Eternity Natural Emerald offered precision-cut Afghan emeralds, including “star” (left), princess (center), and baguette cuts (right, ranging from 6 × 3 mm to 5 × 2 mm). Photos by Robert Weldon/GIA, courtesy of Eternity Natural Emerald.

amined the original material (called “pencil rough” for its We also saw a 12.52 ct cushion-cut emerald (figure 9) long and thin shape). The color was retained even when that came from a 60 ct Afghan rough. The stone was diffi- cut into small stones. cult to cut because the rough was highly fractured and This rough is typically not treated, but a consistent color zoned. Also from the 15,000-carat parcel purchased supply of Afghan emerald is difficult to obtain. Prices are this year were four stones that did not require enhance- high, and negotiating is complex. Security concerns ment, the largest of which weighed 4.61 ct. Mr. Groom es- make it difficult to move rough in the country, and ma- timated that, given the same size and quality, the value terial is often smuggled to Dubai for the international difference between treated and untreated emerald ranges market. To purchase the material, the company makes from 20% to 100%. four to six buying trips a year, with permanent buyers lo- Also on display was a 17.14 ct ruby that had the intense cated in Kabul and the Panjshir Valley. Much of the red color of marble-hosted material and a slightly sleepy rough consists of the pencil crystals used for cutting pre- transparency. The untreated ruby was cut from a 45.37 ct cision melee. Once the pencil rough is sawn and pre- rough, part of a parcel of more than 1,000 carats, purchased formed, the stones are cut for maximum brightness and directly from Tajik miners in May 2015. While this rough the tightest measurement tolerances possible. All melee is available within Tajikistan, Mr. Groom said the material is cut in Sri Lanka. is not easily found on the global market. The asking prices The emeralds were displayed in a variety of cuts and for the rough were high and firm. The parcel was much sizes. Most of the production is between 2 and 4 mm; they more difficult to evaluate than ruby from Myanmar or try to cut the melee within 0.05 mm tolerance. Mr. Groom Mozambique, as the rough was highly fractured. This is expects to unveil 10,000–15,000 carats at the 2016 JCK not uncommon for Tajik ruby, and it makes determining show in Las Vegas. Eternity Emerald is also purchasing the yield and quality of the finished stones problematic. rough from Zambia and Brazil to ensure a continuous sup- Due to the fracturing of the rough, heat treatment may not ply of melee. be a viable option for color improvement. The parcel

Figure 9. This 12.52 ct cushion-cut Afghan emerald Figure 10. The decision to recut a 21.17 ct ruby into came from a highly fractured and color-zoned 60 ct this 17.14 ct gem added substantial value. Photo by rough. Photo by Robert Weldon/GIA; courtesy of Eter- Robert Weldon/GIA; courtesy of Eternity Natural nity Natural Emerald. Emerald.

GEM NEWS INTERNATIONAL GEMS & GEMOLOGY SPRING 2016 85 Figure 11. The surface-breaking fissure in this faceted Figure 12. Prior to treatment, the highly visible fissure Paraíba tourmaline (left) is less visible after cleaning detracted from the rubellite’s clarity (left). After treat- and filling (right). Photos courtesy of Eternity Natural ment, the fissures were less visible, and the stone had Emerald. a more uniform clarity (right). Photos courtesy of Eternity Natural Emerald. yielded a total of nine faceted stones, none of which were Ltd. (New York) showed the authors a 5.06 ct bright yel- heat treated. The largest, a 21.17 ct stone, was cut from the lowish green emerald from China’s southwestern Yunnan original 45.37 ct rough. A large black inclusion was still province. The stone had some eye-visible inclusions, visible after cutting. After being shown to several potential mainly fissures (figure 13). Other than a few tiny chips buyers, the ruby was recut to 17.14 ct. The inclusion was along the girdle, the cut gave the emerald a very elegant less visible in the resulting gem (figure 10), and the color appearance. Mr. Nassi purchased the stone from a reliable and brightness were also improved. Mr. Groom said recut- Thai gem dealer who bought it from a Pakistani merchant ting increased the ruby’s overall value more than 30%. who obtained it along the China-Pakistan border. Since At the booth, we also saw photos of their clarity-en- Mr. Nassi is a cutter who deals with many antique jew- hanced . Clarity Enhancement Laboratories elry pieces mounted with stones, he usually recuts stones (CEL) performs the filling of the surface-reaching fractures. before selling them. He kept this emerald “as is” due to Mr. Groom pointed out that fracture filling of tourmaline the superb quality and size for this specific source. The is nothing new. Most of the material he has seen in the stone was certified by the American Gemological Labo- market has been filled with oils and resins, often without ratory as without oil treatment, with China as the coun- disclosure, since the trade has not traditionally thought of try of origin. fracture filling as a way to improve tourmaline’s apparent China’s only economically viable emerald deposit is lo- clarity. In August 2015, CEL announced tourmaline clarity cated in Malipo County in Yunnan province. The deposit enhancement service. The process, which is similar to its was first discovered in the early 1990s but has never been ExCel method for filling emerald fractures, is offered in their New York City laboratory for all colors and varieties of finished tourmaline. This treatment is not available for Figure 13. This 5.06 ct emerald from China’s Yunnan rough material. province is one of the finest from this source. Photo Although they will fill any variety and color of tourma- by Robert Weldon/GIA, courtesy of 100% Natural line, CEL has mostly received Paraíba (figure 11), rubellite Ltd. (figure 12), and bicolor material. Mr. Groom attributes this to the intrinsically higher values for these varieties. These color varieties often have surface-reaching fractures, and the filling process makes the material much more marketable. Since there is a high demand for these types of tourmaline, treated goods are still of value to dealers. Mr. Groom hopes to promote CEL’s clarity enhancement method as a positive thing that will be fully disclosed through the value chain. Tao Hsu and Andrew Lucas

Rare emerald from China and pink sapphire from Sri Lanka. At the AGTA show, David Nassi of 100% Natural

86 GEM NEWS INTERNATIONAL GEMS & GEMOLOGY SPRING 2016 the necklace itself was unattractive, Mr. Nassi immedi- ately saw potential in the sapphire. He estimated the weight of the mounted stone and made an offer to buy the necklace. The stone, which was abraded with multiple scratches, lost two carats in its recutting but showed a dra- matic improvement. Tao Hsu and Andrew Lucas

Fordite from the Corvette assembly plant. cut- ter and mineral specimen collector Jason Baskin of Jay’s Minerals (Flemington, New Jersey) presented some spec- tacular freeform fordite cabochons, a byproduct of an au- Figure 14. Due to the fissures in Chinese emerald, tomobile painting process that is long gone. stones are usually marketed as mineral specimens. Workers once painted automobile bodies on train cars, This emerald crystal is still in the matrix. Courtesy of which are commonly used on large assembly lines. As the Yunnan Emerald Magazine. paint was sprayed onto the target, the overspray collected on the train cars, and the accumulated layers of excess paint went together with the painted car body to the oven. The factory removed the accumulation periodically to extensively prospected or mined. Emerald specimens and clean the working platform and possibly recycle the paint. crystals are extracted as the byproduct of the tungsten and Mr. Baskin was informed by his contact in the factory that tin deposit. Geologically, the ore body occurs in a core it takes about 997 layers of paint to build a one-inch-thick complex and is related to granitic intrusions in that area. fordite slag specimen (figure 16). Since hand spraying has Geochemical studies revealed that the trace element vana- been replaced by powder painting, fordite is no longer pro- dium concentration is about one magnitude higher than duced, and the material on the market is all that exists. that of , indicating that V is the predominant Fordite was first collected at Ford Motor Company in chromophore in Yunnan emerald. Michigan in the 1940s. The material saved from the 1960s The size and quality of this emerald are rare for Yun- and 1970s has the boldest colors, since cars were painted nan. Since the stones contain abundant fissures, most of in very bright colors during that period. the production is sold as mineral specimens or ornamental Mr. Baskin was introduced to fordite about three years pieces (figure 14). A very small percentage can be faceted ago by a friend and fellow gem cutter whose uncle worked for jewelry. As the local government pays more attention at the Corvette assembly plant in Bowling Green, Ken- to this emerald resource, new development and further ex- ploration are expected. Mr. Nassi also showed us an intensely saturated 24.69 ct Sri Lankan pink sapphire (figure 15), from a necklace he Figure 16. Three fordite slag specimens alongside a had obtained from another estate jewelry dealer. Although partially open piece that shows paint layers with vari- ous colors and thicknesses. Photo courtesy of Jay’s Minerals.

Figure 15. This 24.59 ct Sri Lankan pink sapphire was removed from an estate necklace and recut to bring out its full potential. Photo by Robert Weldon/GIA, courtesy of 100% Natural Ltd.

GEM NEWS INTERNATIONAL GEMS & GEMOLOGY SPRING 2016 87 Figure 17. Different patterns may be exposed when Figure 18. The finished pieces shown here are some of the fordite material is cut open. The original profile of the finest fordites on the market. Photo by Orasa the paint slag can be kept as well. Strata and concen- Weldon/GIA; courtesy of Jay’s Minerals. tric color circles are some of the most spectacular pat- terns. On the left is a 32.36 ct (52 × 64 mm) specimen; the one on the right is 41.86 ct (28 × 73 mm). Both pieces were polished by Jason Baskin. Photo by Preto topaz mines two decades ago. Topaz has been known Robert Weldon/GIA; courtesy of the Clamshell. from this area of Minas Gerais since 1768 (P.C. Keller, “The Capão topaz deposit, Ouro Preto, Minas Gerais, Brazil,” Spring 1983 G&G, pp. 12–20). Although mining was extensive at Ouro Preto in the tucky. Mr. Baskin and his friend now own a substantial col- mid-1990s (D.A. Sauer et al., “An update on Imperial topaz lection of the material from that location. Mr. Baskin is from the Capão mine, Minas Gerais, Brazil,” Winter 1996 also pursuing other sources, including Lincoln-Mercury G&G, pp. 232–241), the Kreis family confirmed that there paint from a Canadian plant and Ford paint from Detroit. is currently no large-scale mining. They visited the area He is also looking for fordite from Harley-Davidson mo- after a collector informed them of a 615 ct crystal with ex- torcycles to fulfill the appetite of Harley lovers. ceptional color and clarity (figure 20). According to their The color layers and patterns of polished fordite are eye- contact, the crystal is “old production” mined at least 20 catching, and experienced cutters know how to unveil its years ago. After analyzing the rough over a period of four most beautiful side (figure 17). Because it is composed of months, the family purchased it in December 2015 with paint, the material is very light. Protection such as a dust mask is necessary during the cutting and polishing processes. Figure 19. The Imperial Flame, a magnificent natural- Mr. Baskin noted that jewelry designers and hobbyists color Brazilian topaz, was cut from a 615 ct crystal re- purchase most of his fordite, though he also sells the cut covered some 20 years ago. The finished 89.53 × 20.56 material (figure 18) through other gem dealers. Some of the × 19.15 mm sculpture weighs 332.24 ct. Photo cour- knobs from the heaters and gear shifters in the old tesy of Sonja Kreis Unique Jewelry. Corvettes had a piece of embedded plastic; clients have him cut Corvette fordite to replace that plastic. Pricing ranges from $20 to several hundred dollars apiece. A very rare type of fordite from 1972 with large metal flakes sold for $400 once it was cut into a 40 × 30 mm cabochon. Tao Hsu and Andrew Lucas

Imperial Flame topaz sculpture. One of the 2016 Tucson show’s most noteworthy gems was a 332.24 ct freeform Imperial topaz (figure 19) at the GJX booth of gem cutter Alexander Kreis (Sonja Kreis Unique Jewelry, Niederwor- resbach, Germany). Topaz with this red, pink, or orangy yellow color component is rare and highly sought after in the trade. Named the “Imperial Flame” by the Kreis fam- ily, the crystal was reportedly recovered from Brazil’s Ouro

88 GEM NEWS INTERNATIONAL GEMS & GEMOLOGY SPRING 2016 faceting and carving to produce the reflective, grooved sur- faces. The fashioning process yielded a spectacular gem measuring 89.53 × 20.56 × 19.15 mm. At 332.24 ct, it had a finished yield of 54%. Intended as an arresting gem sculpture for a connois- seur or high-end collector, the piece is for sale. Duncan Pay GIA, Carlsbad

Update on the Scorpion tsavorite mine. At the AGTA show, Bruce Bridges (Tsavorite USA Inc.) detailed current activity at the Scorpion mine in Kenya and showed some new production (figure 22). The mine lay dormant for more than five years after the 2009 murder of owner Figure 20. The original 615 ct Imperial topaz crystal Campbell Bridges, who originally discovered tsavorite. from which Alexander Kreis fashioned the 332.24 ct While waiting for the courts to hand down verdicts, the Imperial Flame. Photo courtesy of Sonja Kreis Bridges family and their employees were the target of nu- Unique Jewelry. merous death threats. In January 2015, after four of the eight defendants received sentences of 40 years without parole, the mine reopened with a larger scale of operations the objective of cutting the largest, highest-quality Imperial than ever before. topaz known. Activities expanded for a variety of reasons. As a cor- Due to the gem’s perfect basal cleavage, cutters must poration rather than a small family operation, the Bridges avoid grinding the stone perpendicular to the cleavage family felt that they were less of a target for criminals. The plane, while also accounting for inclusions that might Bridges also found that the demand for tsavorite rose ex- cause the stone to break on the wheel. According to Sauer ponentially during the mine’s closure. With a limited sup- et al. (1996), well-formed, largely inclusion-free crystals ply and greater popularity, the higher selling price has made typically yield up to 2 ct per gram (5 ct), which is a 40% larger-scale mining more feasible. recovery rate. Cutting the Imperial Flame took approxi- There are 80 to 100 workers at the Scorpion mine, three mately eight days, spread over a period of 3–4 weeks, to times the number employed when it closed in 2009. The allow Kreis to make trial carvings with smaller Imperial miners work in continuous shifts seven days a week. topaz pieces to test his cutting concepts. The cutting Mechanization has increased to include more powerful process began with sawing off the included portions and generators and 15-kilowatt fans for ventilation in the tun- grinding to shape the solid crystal (figure 21), followed by nels. The tunnel is now below the oxidized zone, requiring a blast approximately every half meter of forward progress.

Figure 21. After trimming away included portions of the crystal’s base, Alexander Kreis gently removes Figure 22. The new production from the Scorpion any surface-reaching inclusions and begins to shape mine includes these 6.48 ct and 3.43 ct tsavorites. the crystal to his own unique design. Photo courtesy Photo by Robert Weldon/GIA, courtesy of Tsavorite of Sonja Kreis Unique Jewelry. USA Inc.

GEM NEWS INTERNATIONAL GEMS & GEMOLOGY SPRING 2016 89 The stronger fans allow the ventilation system to remove the smoke and dust in about two hours rather than the full day previously needed. They have also invested heavily in .. trucks, buildings, jackhammers, drills, and more explo- sives. Campbell Bridges’s original campsite and tree house remain intact. The main focus of the current operation is the Bonanza tunnel, also called tunnel 4, which was Scorpion’s most prolific tunnel in the 1980s. They are also working the ad- jacent tunnel 2, the largest producer in the 1990s. Tunnel • 2 produced five kilograms of facet-grade material over one carat from one pocket during this period. A few kilometers from Scorpion is mine GG2, which typically produces tsa- Figure 23. Prior to cutting, the Bridges operation sorts vorite with lighter tones. GG2 is an open-cast operation on the tsavorite rough into categories by size, color, clar- a hill, with plans to move into a tunnel phase later this ity, and shape. Photo courtesy of Tsavorite USA Inc. year. An untouched surface deposit near tunnels 2 and 4 is also in development for open-cast mining, and the Bridges have high hopes for it, as the ratio of yield to waste is high on new deposits. Other sources include GG3, which is sev- Even with the new investment and expenses, current eral kilometers away and primarily uses tunnel mining, production is only about 10% higher than before the mine and Snake Hill, which is one kilometer from Scorpion and was closed. Electromagnetic surveys have shown exten- has been mined by both open-cast and tunnel methods. sive anomalies that indicate tsavorite enrichment zones. Snake Hill is also a source. These deposits have Most experts believe the reserves are very good, and Camp- been put on hold in favor of tunnels 2 and 4 and GG2, as bell Bridges himself believed he could follow the lines of well as the untouched surface deposit. the Scorpion mine’s saddle reef structure and the nose of There is now greater sophistication and manpower in the folds for two kilometers while producing tsavorite in Tsavorite USA’s mining process. The drill team bores large pockets. Each tunnel at Scorpion is about 200 meters deep. holes in the tunnels and then places the explosives. After These reserves must be balanced, however, with the grow- the blast, the air is flushed out by the new ventilation sys- ing cost of delving every meter further into the earth. tem. The removal of waste has been accelerated by the use Bruce Bridges told us that “demand is through the roof” of a mono winch, which allows up to eight tons of waste to for tsavorite. With its popularity potentially on the rise, be removed hourly. The waste is hauled to the dump site, Tsavorite USA will have to outsource rough. Melee de- where it is separated from the rock face. The mine manager mand is at an all-time high, particularly in China and other examines the rock face for tsavorite crystals or nodules, also Asian countries, where it far exceeds the available supply. checking for indicators in the reef such as , quartz, Mr. Bridges foresees overall growth for tsavorite through and pyrite. Depending on the indications, teams will either continue blasting or extract material with hammer and chisel until the gem body is reached. At that point, miners Figure 24. The Bridges intend to keep their tsavorite use sharpened six-inch nails and finally their hands. The cutting in Kenya for as long as it is economically vi- gem-bearing specimens are bagged and marked for quality. able. Photo courtesy of Tsavorite USA Inc. Once out of the mine, the material is washed and the tsa- vorite crystals are separated from the host rock. Sieves are used to sort the production by size before it is graded on a sorting table (figure 23). It is then bagged, sealed, and taken to Nairobi by ground or air, depending on its value. All rough that can be cut to yield a 50-point stone or higher will be cut in-house in Kenya, while the cutting of smaller rough is outsourced. Campbell Bridges learned to cut gemstones in Idar-Oberstein, Germany, and he later trained local Kenyans. One expert cutter on-site is cutting at least 200 stones a month. The Bridges family is proud of their high cutting standards and that they cut most of the high-quality rough in Kenya (figure 24). They also pay a higher export value for finished cut stones than rough, gen- erating more revenue for Kenya. The stones are exported to Tsavorite USA’s main sales office in Tucson or to cus- tomers worldwide.

90 GEM NEWS INTERNATIONAL GEMS & GEMOLOGY SPRING 2016 television sales, but he wants to keep as much cutting in Kenya as possible. Challenges for the company include possible changes in the political scene, mining regulations, and the threat of crime and violence. Upon returning to Kenya, Mr. Bridges reported to the authors that death threats had started again. Tao Hsu and Andrew Lucas

Jewelry Television in Tucson. Jay Boyle, senior gemstone buyer at Jewelry Television (Knoxville, Tennessee), spoke with us about the importance of the Tucson shows to JTV as well as the impact of television on the trade at large. We saw him conduct live broadcasts from the gem fair and in- terview dealers at their booths (figure 25). Mr. Boyle said the key to buying for television is finding beautiful gems at low market prices and being able to tell the story and romance the stone while educating the customer. He pointed out that finding beautiful stones is easy, but it is considerably more difficult to obtain them at a great value price point that is right for the television network’s customers; in fact, there is an art to the process. Major deal- Figure 26. During times when prices are firm, buying ers from all over the world come to Tucson and sell all va- decisions and quality control are even more crucial. rieties of gemstones, making it advantageous for JTV to Jay Boyle and Natalie Tjaden of Jewelry Television attend. These dealers frequently sell stones among them- keep this in mind as they examine gemstones in a selves at true wholesale prices, so Mr. Boyle has the oppor- dealer’s booth. Photo courtesy of Jewelry Television. tunity to find attractive stones at the right price and value

for television (figure 26). In Tucson, buyers can survey Figure 25. Broadcasting from the gem shows helps everything coming from the sources, including new pro- Jewelry Television educate viewers about colored duction, and discover the true market prices, all within one gemstones. Photo courtesy of Jewelry Television. week. He added, “If you have a reputation as a serious, knowledgeable buyer that buys in quantity and has cash to buy, you can find the real market price.” According to Mr. Boyle, the best time to purchase is when the material first hits the market. Another good time to buy is when there is a sudden increase in production. In 2001, JTV bought a large tsavorite lot containing more than 2,200 carats of material ranging from 2 to 10 ct per stone. The color and clarity were fine, and the price was a good value at $350 per carat. They took a small margin and sold the production quickly; 5 to 7 ct gem-quality tsavorites went for $500 per carat. Today, the wholesale prices for the material are many times that price, and longtime cus- tomers see the value of purchasing at the right time. An- other successful venture began in 2006, when Mr. Boyle started buying “best of show” material of all gem species, at the best price possible. These stones were sold during special broadcasts called “The Vault” (figure 27). The high- est price recorded on the show was a $400,000 sapphire. Regular viewers know that at times JTV has sold remain- ing inventory below cost, and some actually make a busi- ness out of reselling this merchandise. Founded in 1993, Jewelry Television broadcasts 24 hours a day, reaching 84 million homes. Ninety-five per- cent of the gemstones sell for $10 to $5,000 apiece. Viewers are introduced to gemstones they had never encountered,

GEM NEWS INTERNATIONAL GEMS & GEMOLOGY SPRING 2016 91 such as padparadscha sapphire, Paraíba tourmaline, and color-change garnet, while learning about the gem business and how to recognize bargains. Some steady customers tune in for 10 hours a day. When Jewelry Television first started offering loose colored stones, they were thrilled to sell $15,000 in an eight-hour period. Now they sell up to $400,000 of loose colored stones in an hour, and it is com- mon to ship between 18,000 and 25,000 packages in one day. Mr. Boyle feels that JTV is driving business throughout the retail industry by promoting colored stones, as some viewers will learn about a given gemstone and then visit a local jeweler to make a purchase. Between 30% and 35% of the company’s $400–$500 million in annual sales are online at jtv.com, which com- plements rather than replaces television sales. The website is also used to clear inventory from television at liquida- tion prices. Due to the extremely high cost of airtime in the U.S., JTV must not only sell the entire inventory, but also sell it in a short time. That means the Internet can be used to move leftover inventory while fresh, faster-moving products are sold on television. The network plans to even- tually host web-only streaming video broadcasts. Interestingly, one of the most successful periods for Jewelry Television was during the global economic crisis. While many industry players had stopped buying by Janu- ary 2009, Mr. Boyle had learned over the years that dealers sell below cost during a recession. At the 2009 Tucson Figure 28. The “Rainbow Over Montana” bracelet show, he bought $7 million in gemstones, including $3 contains 76.83 carats of Montana sapphire (71.42 million in tanzanite from one dealer alone. Since Mr. Boyle carats rough and 5.41 carats faceted). The ring from had well-established buying relationships with dealers, the same collection contains 11.57 carats of rough they were willing to accept his plan to promote a buying and 1.12 carats of faceted Montana sapphires. Photo opportunity for TV customers. The promotion of below- by Robert Weldon/GIA; courtesy of Paula Crevoshay.

Figure 27. The pendant worn by host Dawn Tesh (left) market prices created a frenzy of activity for Jewelry Tele- contains a 102 ct aquamarine that was sold during a vision. While these bargains were more plentiful in 2009, 2009 broadcast of “The Vault” on Jewelry Television. Mr. Boyle said there are still great opportunities below Photo courtesy of Jewelry Television. market value every year in Tucson. Although he was buy- ing less than usual this year, JTV still actively sought ma- terial throughout the show. Among the stones we saw Mr. Boyle buying were rhodochrosite and Ethiopian . Tao Hsu and Andrew Lucas

Paula Crevoshay’s American Collection, plus jewelry with nontraditional gemstones. Paula Crevoshay’s American Collection, created as a cultural and artistic inheritance for future generations, featured gemstones from the United States. The first pieces we saw were from her “Rainbow Over Montana” collection of rough and faceted Montana sapphires (figure 28). She used the faceted sapphires to show “the story of light” told by the gemstone after the human contribution of cutting, while the crystal slices dis- play the natural hexagonal shape and luster of the flat crys- tal faces. The blue faceted stones represent the “Big Sky Country” of Montana, and the crystals demonstrate the range of rainbow colors in Montana sapphire.

92 GEM NEWS INTERNATIONAL GEMS & GEMOLOGY SPRING 2016 Figure 29. This 31.34 ct bicolor tourmaline pin, which Figure 30. While not as large as some of the other contains gemstones exclusively from the Stewart colored stones used by Paula Crevoshay, the intense Lithia mine in San Diego County, has an emotional color and unique cut of the 2.77 ct Oregon sunstone connection for the artist. Photo by Robert Weldon/ makes this ring one of her favorite pieces. The center GIA; courtesy of Paula Crevoshay. stone’s color is complemented by 3.24 carats of red . Photo by Robert Weldon/GIA; courtesy of Paula Crevoshay.

The next piece was a pin featuring a 31.34 ct bicolor pink and green tourmaline (figure 29) from the Stewart Lithia mine in San Diego County, California. The stone ever seen. The stone features the trademarked “Medicine was purchased back from a customer who had bought it Wheel” cut by award-winning lapidary Larry Woods. The from Paula’s late husband, George Edward Crevoshay, who ring also contains red and . first cut the stone more than 30 years ago. The pink and While visiting her booth at the AGTA show, the au- green tourmaline melee in the piece was also cut by Mr. thors also noticed some nontraditional stones ingeniously Crevoshay and came from the Stewart Lithia mine. Besides incorporated into jewelry. The first two pieces we viewed featuring gemstones from a famous U.S. mine, this piece contained center stones of sphalerite (figure 31, left) and carries the sentiment of a great love that inspired Paula sphene (figure 31, center), both in pendants. For Ms. Crevoshay to move from painting and sculpture into the Crevoshay, creating jewelry is all about working with light. world of gemstones and creating jewelry. How she selects and combines gems depends on properties The third piece (figure 30) was a ring that contained one such as , bodycolor, luster, and phenomenal of the most intense red Oregon sunstones the authors had optical effects.

Figure 31. These Paula Crevoshay jewels include gems not typically used in jewelry. Left: The 8.25 sphalerite pen- dant creates an eye-catching fire, complemented by the play-of-color of the opal and the colorful sparkle of the di- amond melee. Center: The green color of the 11.78 ct sphene pendant is accentuated by tsavorite melee, with the orange fire offering a striking contrast. Right: This dragonfly pin features a 38.24 ct drusy as the in- sect’s body. The drusy’s iridescence and sparkle creates a shimmering effect that is intensified by the orient of the Tahitian cultured pearl used for the head. Photos by Robert Weldon/GIA; courtesy of Paula Crevoshay.

GEM NEWS INTERNATIONAL GEMS & GEMOLOGY SPRING 2016 93 Both sphalerite and sphene are highly dispersive, and the flashes of rainbow color created by the ex- cite the eye. For the sphalerite piece, she added Mexican opals showing a rainbow of colors, combining a highly dispersive gem with phenomenal accent stones to create a dance of colors across the pendant. The pendant also contains cognac and colorless diamonds to create even more of a symphony of colors. Ms. Crevoshay chose the sphene for its high dispersion and her attraction to the green bodycolor. As with the sphalerite pendant, she added Mexican opals showing a subtle rainbow of phe- nomenal colors. With both pieces, she combines gemo- logical knowledge with art to create jewelry that paints with the surrounding light. Another piece that caught our attention was a dragon- fly containing rainbow hematite drusy as the insect’s body (figure 31, right). With the hematite, Ms. Crevoshay was able to highlight the iridescent colors and sparkle of the drusy. She finds that the rainbow colors of the hematite are not as bold as those caused by dispersion from the sphene and sphalerite but still have a seductive effect. Public awareness of gemstones such as sphene and sphalerite has been growing thanks to high-end designers such as Paula Crevoshay and through mass marketing of commercial jewelry on television. Ms. Crevoshay told us Figure 32. The “Wheel of Light” Numinous pendant she often piques customers’ interest by informing them contains an 825 ct carved quartz centerpiece. Differ- about some of these lesser-known gem materials and how ent rough gems have been placed into a channel light interacts with them. The authors found this to be a drilled into the quartz by the lapidary artist, which fascinating look at how stones that were once a gemologi- was then set in 24K gold. Photo by Robert cal novelty are becoming more widely known. Weldon/GIA; courtesy of Nature’s Geometry. Tao Hsu and Andrew Lucas

Wheel of Light’s mesmerizing optics. Lapidary artist Brian Cook, of Tucson-based Nature’s Geometry, is astonished virtually disappear. This is how the luminosity and color that the optical designs he has experimented with and re- of the included crystals is accentuated.” fined for more than 25 years have finally come of age. Ap- Goldsmith Paula Brent, a longtime collaborator, brings preciation for his work culminated with a first-place award the pieces to completion. The wheels are crafted using 24K in this year’s AGTA Spectrum’s Fashion Forward category gold, which accentuates the strength and purity of the fin- for his “Wheel of Light” Numinous pendant (figure 32), ished object. which graces the cover of this issue. Mr. Cook says that the work of Nature’s Geometry is The 825 ct quartz center stone of this piece was carved futuristic and imaginative, but at the root of it is a mysti- to resemble a rounded disk with a softly contoured apex, cal, ancient attraction to the mineral world. The company or dome. After drilling the apex, Mr. Cook carefully in- is connecting with innovative young designers and is ap- serted rough crystals of Paraíba tourmaline, haüyne, ruby, preciative that the “millennial” generation is affected by and garnet. The channel was then filled with the beauty and power of gems and hungry for a nontradi- jojoba wax and hermetically sealed with a quartz plug. The tional approach to jewelry. Mr. Cook has been involved trapped “inclusions” are visible if the disk is observed from with the exploration for and marketing of copper-bearing the side. As the disk is turned, with the viewer gazing tourmaline from Paraíba, Brazil, since 1988, shortly after down the apex, an interesting optical effect is noted: The its discovery. “The rough I saw were often too small for colors corresponding to the included gem rough are re- cutting, and the material was always extremely rare. But vealed as concentric rings. To the eye, the ringed colors ap- the color was so vibrant that I kept looking for a way to pear as painterly brushstrokes. Mr. Cook explained that the bring that ‘electrifying’ color to a greater audience.” quartz vessel becomes both a frame and a mirror for what With the Wheel of Light numinous pendant, Brian the eye sees. “The colors are amplified by the quartz, re- Cook has done just that. flected off its inside surface. The jojoba wax, with a refrac- Robert Weldon tive index close to that of quartz, causes the channel to GIA, Carlsbad

94 GEM NEWS INTERNATIONAL GEMS & GEMOLOGY SPRING 2016 GILC 2016. The International Colored Gemstone Associ- outlined the convoluted path from small-scale or individ- ation (ICA) held its annual Gemstone Industry & Labora- ual miner through a series of brokers to cutting and the tory Conference on February 1 during the Tucson shows. “end user” market, where it may go through another series Invited participants included jewelry trade association of dealers before reaching a consumer. Most colored stone leaders, laboratory representatives, academic institutions, sources are overwhelmingly alluvial or placer deposits in and ICA members. This year, other industry members remote areas, making them difficult to centralize. Trace- were welcomed into the afternoon open discussion session. ability is even challenging at the mine, where it is not un- Lore Kiefert (Gübelin Gem Lab, Lucerne, Switzerland), common for material from a different location to be sold presenting on behalf of her colleague Daniel Nyfeler, spoke without disclosure. Traceability from cutting centers can on age determination by radiogenic isotopes. Laser abla- improve as host countries introduce limits on rough ex- tion–inductively coupled plasma–mass spectrometry (LA- ports and begin developing cutting facilities, which has ICP-MS) has enabled the Gübelin Lab to use radiometric happened in parts of Africa, South America, and Asia. dating to test inclusions at or near the surface of materials The conference proceeded to an open session for invited such as corundum and emerald, which do not have radioac- participants to discuss topics of concern, including: tive atoms. When traditional methods such as observation 1. The increasing use of color enhancement and “anti- of inclusions and growth structure and trace element analy- scratch” ( carbide) coatings, which are virtually sis lead to more than one possible country of origin, radio- invisible and sometimes too thin to be detected with metric dating can furnish the decisive data. U/Pb decay in instruments. With advances in nanotechnology, more zircon has been well documented as a means to establish research is needed to develop detection strategies. an approximate timeline for known sapphire and emerald 2. The inconsistent use of descriptive terminology in populations. The corundum timeline established the oldest laboratory reports, a topic carried over from the 2015 population as African, with an age of 450–650 million years conference. The laboratories maintained that they (Ma), and the youngest as Colombian, at 10 Ma. Emerald were responding to the demands of the trade. One formation ranged from South Africa at 2900 Ma to Colom- participant pointed out that the terms “pigeon’s bia at 65–35 Ma. This method is limited when the gem- blood” and “royal blue” had no meaning in Chinese stone presents no analyzable inclusions or has been treated. culture until about ten years ago. Since then, they James Shigley (GIA, Carlsbad) presented the Institute’s have become “deeply implanted,” and a seemingly latest research findings. GIA’s work with color analysis has irreversible demand has been created for the level of its foundation in observation and color grading of colored distinction that these terms confer. diamonds. Dr. Shigley noted that the visible spectrum is 3. Unethical or fraudulent use of lab reports. An example not the only cause of color; in fact, the face-up appearance cited is the treatment of a gemstone after it had re- is influenced by about 15 factors, including the emission ceived a “clean” report. Another is the manufacture spectrum of the light source, the absorption spectrum of of both treated and synthetic diamonds to match an the stone, and the color sensitivity of the eye. Since hu- existing natural diamond report. GILC participants mans are more adept at distinguishing differences than stressed the importance of checking reports against similarities, the use of master stones and bracketing be- stones through every phase of the grading process. tween pairs is well suited for visual grading. GIA uses in- 4. The use of “undetermined” on a lab report in regard strumentation to supplement visual grading in face-down to treatment or synthetic origin. Some participants evaluation of round near-colorless D to Z diamonds; how- voiced concerns that such determinations are beyond ever, fancy-color diamonds are graded face up. GIA has the technologies of labs, or that the word “undeter- been working on analytical tools that can “detect” color mined” left untreated natural diamonds vulnerable in the same way that the human eye processes it. to being matched with treated or synthetic stones. Bruce Bridges (Tsavorite USA, Inc.) asked whether gems can be reliably traced from the source to the con- At the conclusion of the conference, it was announced sumer. Today’s consumer wants to know where products that AGTA had revised its code of ethics and principles of come from and how their manufacture affects both the en- fair business practice. ICA is proposing to adopt AGTA’s vironment and workers. Vertically integrated companies code of ethics, due diligence protocol, and source disclosure can promote traceability and control over ethical sourcing, language as a basis for its own code. but the business model cannot be applied to the small-scale Donna Beaton operations that characterize most of the industry. Bridges GIA, New York

For More on Tucson 2016 Tucson 2016: Take a virtual tour of the gem fair with our in- depth reports on colored stone trends, unique designs, and industry forecasts. Visit www.gia.edu/gems-gemology/spring-2016-gemnews-tucson-overview, or scan the QR code on the right.

GEM NEWS INTERNATIONAL GEMS & GEMOLOGY SPRING 2016 95 Vohitany A F R I C A

REGULAR FEATURES Tiramena 0 • Esira Maromby Ankazoaba i~ Old Uranium Mines Madagascar 0 0 COLORED STONES AND ORGANIC MATERIALS Andranondambo • Tranomaro Blue sapphires from a new deposit near Andranondambo, Madagascar. In January 2016, author VP was informed by Ifotaka Nirina Rakotosaona (Societe Miniere du Cap, Madagascar) and Jack Mampihao of a sapphire rush in the south of the 0 41km island near Andranondambo. The blue sapphires (figure 33) Amboasary Tolanaro (Fort Dauphin) are reportedly from a primary deposit and similar to those produced near Andranondambo, the region that put Mada- gascar on the map as a world-class sapphire source two decades ago (D. Schwarz et al., “Sapphires from the Andra- Figure 34. According to miners, the new deposit is lo- nondambo region, Madagascar,” Summer 1996 G&G, pp. cated near Vohitany, north of Tiramena. This remote 80–99). Details emerged as miners returned from the rush area is only accessible by foot. in February. According to these firsthand accounts, the new mines are located near Vohitany, north of Tiramena ated with kaolin. Out of more than 300 stones studied, (figure 34). They are only accessible by foot, and it takes only one showed some indication of weathering. This sug- about a day of walking from Tiramena to reach the area. gests that the material is from a primary deposit. The The author’s contacts in Madagascar did not consider stones were euhedral transparent crystals with strong blue it safe to travel to that area, which is known to be a haven color zoning. Overall, the material was very similar to the for bandits, called malaches or dahalo. In early February, specimens the author collected in Andranondambo and the author learned from Karim Guerchouche (Premacut, Tiramena during visits in 2005, 2008, and 2010. Bangkok) that a 1 kg parcel of the new material had arrived Sixty-three stones from the original parcel (mainly clean in Thailand. The owner, Isaac Stern, wanted to perform and milky specimens) were selected for a heat treatment some heat treatment experiments with Premacut. This of- experiment. Fifteen other stones, most of which hosted in- fered us a chance to conduct a preliminary study of the ma- clusions, were studied at GIA’s Bangkok lab (figure 35). The terial before visiting and collecting samples at the site. study confirmed their similarity to GIA reference samples Most of Mr. Stern’s parcel consisted of rough weighing from Andranondambo; details will be published in a News between 1 and 4 ct. The largest stone was an etched crystal from Research entry on the GIA website. weighing nearly 15 ct (again, see figure 33). The parcel was The new stones showed a medium to high iron content composed of attractive, well-formed crystals still associ- (between 300 and 1100 ppma), consistent with the classic Andranondambo material. Strong blue color zoning and an abundance of negative crystals dominated the inclusion Figure 33. These three rough unheated sapphire crys- tals, weighing (from left) 9.98, 14.56 and 7.7 ct, are re- portedly from Madagascar’s newest rush area. Beside Figure 35. A detailed view of the 15 unheated samples them are heat-treated faceted sapphires believed to selected for a preliminary study. The stones were be from the old deposits around Andranondambo. placed on a light box and are seen here using bright The pear-shaped faceted stone weighs about 4.17 ct. diffused light. Under such conditions, the strong color Photo by Vincent Pardieu/GIA. zoning is obvious. Photo by Sasithorn Engniwat/GIA.

"-.

96 GEM NEWS INTERNATIONAL GEMS & GEMOLOGY SPRING 2016 cordierite occurs in a “vein” (probably a layer) associated with orange and blue cordierite, parallel to other layers con- taining kornerupine or blue spinel. The cordierite vein is about 1.50 m thick and wide and is apparently contained in a kornerupine layer. Cordierite is usually found in a meta- morphic environment, but the layered appearance, with each band containing specific minerals in thicknesses of about 1 m, is reminiscent of metasomatic deposits. The as- sociation of cordierite with kornerupine and spinel is already known; blue gem-quality cordierite is found in such a meta- somatic reaction zone in Kenya (C. Simonet, pers. comm., 2015). Figure 36. A blue sapphire from Madagascar’s newest To determine the material’s gemological properties, deposit hosts this group of negative crystals. Some three stones were fashioned by Jacques Le Quéré (Auray, crystals host white hairlike diaspore needles, identi- France): a 2.69 ct modified rectangle; a 1.28 ct flat cabochon, fied using Raman spectroscopy. Photo by Victoria cut to obtain a lighter color; and a 4.17 ct parallelepiped, Raynaud/GIA; field of view 1.2 mm. faceted based on the optical directions to best show its trichroism (figure 37). The RIs, measured with a Rayner LED sodium-equivalent lamp, ranged from 1.527 to 1.541 scene (figure 36). Many stones contained bands of minute (n = 1.528–1.530, n = 1.532–1.533, and n = 1.538–1.540). x y z particles, thin needles, and growth tubes. Calcite mineral Interestingly, this crystal presented a biaxial positive char- inclusions were common; we also identified mica and ap- acter, whereas gem cordierite is typically biaxial negative. atite crystals. The trichroism was very strong, as expected with The heat treatment experiment was successful. The cordierite. With a standard dichroscope, the colors ranged light-colored, slightly milky material turned into fine trans- from deep red to orange to grayish brown with a hint of parent, deep blue stones after heat treatment under reduc- blue or purple (figure 38), this last color becoming black at ing conditions for seven hours at approximately 1600°C. a thickness of about 1 cm (figure 39). Hydrostatic SG meas- Most of the included stones broke during the experiment, ured 2.548–2.554. These properties are consistent with probably due to the presence of negative crystals. cordierite, though SG was at the lower end of the range. This exciting discovery suggests that the Andranon- As the rough was sawed, we noticed that the vivid red dambo sapphire deposit is much larger than originally ex- transparent color of the thick crystal turned to orange with pected. The main challenges are the security issues and the reduced thickness. This is the definition of dichromatism, nature of the deposit itself, as the rocks hosting the sap- also known in gemology as the Usambara effect, a varia- phires are very difficult to work. tion of hue that is affected by the optical path length. Vincent Pardieu, Supharart Sangsawong, The UV-visible absorption spectrum was measured on Wim Vertriest, Stanislas Detroyat, Victoria Raynaud, and Sasithorn Engniwat GIA, Bangkok Figure 37. These three gems, weighing (from left) 4.17, 1.28, and 1.28 ct, were fashioned from the same piece of cordierite rough; red is a new color for this gem. Red cordierite from Madagascar. At the Mineral Expo show in Paris in early December 2015, we procured a large piece The specimen originated from a recently explored de- of dark red cobbed rough presented as cordierite. This posit in southeast Madagascar. Photo by Benjamin would be the first documented occurrence of red cordierite. Rondeau. The slightly fractured 3 cm rough offered a magnificent deep red color when examined using transmitted light from a Maglite illuminator. The identity of the rough as cordierite was confirmed using Fourier-transform Raman (FTR) spectrometry. The spectrum obtained showed excel- lent agreement with a reference spectrum for cordierite from Madagascar in the RRUFF database (http://rruff.info). Author TP confirmed that the piece we examined was from the Iakora district, Fianarantsoa province, in southeast Madagascar. Cordierite has long been known in this general area (A. Lacroix, Minéralogie de Madagascar, A. Challamel, Paris, 1922). There is no mechanized mining. According to a miner’s sketch obtained locally by one of the authors, red

GEM NEWS INTERNATIONAL GEMS & GEMOLOGY SPRING 2016 97 Figure 38. Pleochroism of the oval cabochon observed in polarized light in the two orthogonal directions. On this thinner sample (about 3 mm thick), the desatu- rated grayish brown color with a hint of blue or pur- ple is best observed. The stone measures 9.85 × 6.75 mm. Photos by Emmanuel Fritsch. a Unicam UV4. When the material was a few millimeters virtually stopped because of technical and logistical limita- to a centimeter thick, in the direction where red is observed tions. As a result, production has been very limited, and very there is an extremely strong absorption in the violet and blue little information was published about and sapphires areas; this band leads to the red color. The absorption de- from Muling until 1995 (J.X. Sun, “Basalt related to ruby and creases abruptly from about 550 to 685 nm, with only a sapphire in eastern Heilongjiang and reconstruction of pa- weak broad band from about 710 to 800 nm. This leaves a leovolcanic mechanism,” Acta Petrologica et Mineralogica, steep transmission window in the red, which is consistent Vol. 14, No. 2, 1995, pp. 126–132). with the color observed. The shape of the absorption and a According to Aijun Yi, director of mineral resource ad- rapid decrease in the orange-yellow also explains the Usam- ministration in Muling, the region has produced large bara effect. Through a few millimeters, the perceived color amounts of gem-quality eluvial materials since 1994, in- is orange; through a centimeter or more, it is deep red. cluding corundum, brownish red zircon, garnet, and spinel Emmanuel Fritsch (T. Chen et al., “Brownish red zircon from Muling, China,” Benjamin Rondeau, University of Nantes, France Spring 2011 G&G, pp. 36–41). As colored stones became more popular in the Chinese gem markets, interest in ruby Thierry Peclet, Manakara, Madagascar and sapphire from Muling grew accordingly. Patrick Lefebvre, Aix en Provence, France We acquired a parcel of rubies and sapphires from local Yves Lulzac, Nantes, France miners. The stones ranged from 0.8 to 15.2 ct (figure 41). Most exhibited well-formed tabular hexagonal crystals, Ruby and sapphire from Muling, China. Only a few Chinese though some broken sapphires had a tumbled appearance. sources produce gem-quality corundum, such as Changle, The sapphires were pink, yellow, violetish blue, greenish in Shandong province, but sapphires from that location are blue, light blue, and deep blue; there were also near-color- not considered top quality in the trade because of their dark less specimens. Most of the rubies and pink sapphires had hues. An emerging deposit in Muling, in northeast Hei- a purplish component. Samples other than the deep blue longjiang province (figure 40), produces gem-quality corun- material showed high transparency. Rubies and pink sap- dum comparable to some world-renowned sources. The phires exhibited medium red fluorescence under long-wave main deposits are seated in mountain valleys about 70 km (356 nm) UV light and a weak reaction under short-wave from the town center. Corundum was known in Muling as (245 nm) UV. Other varieties of sapphire had no reaction early as 1985; after preliminary exploration, further activity under long- or short-wave UV.

Figure 39. Trichroism of the 9.45 × 6.95 × 5.28 mm cordierite parallelepiped observed in polarized light in the three orthogonal directions to represent the three “extreme” colors of the material’s pleochroism: deep red, black (both seen with a thickness of 9.45 mm), and orange (seen with a thickness of 6.95 mm). Photos by Emmanuel Fritsch.

98 GEM NEWS INTERNATIONAL GEMS & GEMOLOGY SPRING 2016 RUSSIA Irkutsk Ulan-Ude

Khabarovsk Ulaanbaatar

Muling MONGOLIA Harbin

Changchun Shenyang Hohhot Beijing Tianjin Pyongyang Yinchuan Niigata Shijiazhuang Seoul Tokyo

KOREA Ulsan Lanzhou Xían JAPAN Zhengzhou Busan Nagoya CHINA Fukuoka-Shi Nanjing Oita Wuhan Shanghai Kagoshima Figure 42. A detailed structure of whitish needles Chongqing Hangzhou forming a three-dimensional skeleton network in a Changsha Guiyang E A S T C H I N A S E A ruby sample. Photo by Yimiao Liu. Fuzhou Kunming Taipei 0 600km

Nanning Hong Kong Macao latter mineral only occurred as component mineral crystals Figure 40. Muling, the site of an emerging corundum in a multiphase inclusion. Most rubies hosted whitish nee- deposit, is located in northeastern China. dles forming three-dimensional skeleton networks that might be the result of diaspore exsolution (figure 42). Fur- ther microscopic observations under polarized light showed The samples generally showed abraded features and un- characteristic lamellar twining structures in every sample. healed fissures, but some were predominantly clean under Trace element analysis by LA-ICP-MS showed a Cr con- the loupe and large enough to be faceted. Fourteen stones tent of 173–636 ppma in the pink-red series, accompanied were fabricated as parallel polished windows for micro- by a significant level of Fe (1650–2510 ppma) and a notice- scopic examination. Several interesting internal features able level of Ti (36–70 ppma) to add a blue component were visible under the microscope. The inclusions, which through Fe-Ti intervalence charge transfer. This explained mainly appeared as rounded single crystals or multiphase why Muling rubies and pink sapphires always had a purplish syngenetic clusters, were in micron sizes (50–200 µm) and hue. Mg content was about 46–79 ppma, while Ga (13–17 were identified by Raman as and sillimanite. The ppma) fell into the expected range for natural corundum. Yellow sapphires showed the highest Fe content (4480– 4800 ppma); this contributed to their saturated yellow col- Figure 41. Ruby and sapphire rough from Muling ex- oration. Iron content was much lower in blue sapphires, hibited well-formed tabular hexagonal crystal forms; along with an appreciable amount of titanium (80–500 some sapphires showed a tumbled appearance in bro- ppma) as a blue chromophore. Based on color distribution ken pieces. Photo by Yimiao Liu. and transparency, blue sapphires could be grouped as either light blue or deep blue. Most of the light blue sapphires had very high transparency and even color distribution, while deep blue sapphires were less transparent, with hexagonal dark blue color zoning. Among all blue samples, Mg con- tent ranged from 10 to 80 ppma and did not show clear cor- relation to color, while Ga content (10 to 100 ppma) was noticeably higher than in rubies and pink sapphires. At Muling, most rubies and sapphires are found by ca- sual surface digging. Gem-quality corundum usually occurs in eluvial deposits derived from weathered Cenozoic alkali basalts. Unlike other igneous-related deposits known for dark blue sapphires and very limited red material, such as Australia’s Anakie and New England fields (T. Coldham, “Sapphires from Australia,” Fall 1985 G&G, pp. 130–146) and Shandong, China (C. Simonet. et al., “A classification of gem corundum deposits aimed towards gem exploration,” Ore Geology Reviews, Vol. 34, 2008, pp. 127–133), in Muling

GEM NEWS INTERNATIONAL GEMS & GEMOLOGY SPRING 2016 99 ruby production was larger than that of sapphire; over 60% pp. 46–57). The newly acquired crystal was added to the GIA of pink sapphires and rubies were high-quality materials. reference collection. With a chemical formula of MgAl O , 2 4 In some ways, some Muling rubies have competitive ad- spinel belongs to the cubic crystal system. It is often found vantages over Mozambique specimens. Their high color sat- as octahedrons (with o faces), but sometimes dodecahedron urations and particular internal features (whitish needles d faces are visible. This specimen presents a fascinating case forming three-dimensional skeleton networks) resembled of twinning parallel to the octahedral plane O (111), com- those of rubies from Mozambique and might cause confu- monly called “spinel-law” twinning. The general crystal sion in gem markets. On the other hand, blue sapphires from outline is a 12-sided polygon instead of the expected hexa- Muling have a pure blue color with no gray component. The gon. If a spinel crystal shows only o faces, a crystal flattened variety of colors and the amount of fancy sapphires found along the (111) plane will appear as a hexagon. But a spinel in Muling are quite different from sapphires from other clas- with both o and d faces that is flattened along the (111) oc- sic igneous deposits (see again Simonet et al., 2008). tahedral plane will show 12 sides, as in this specimen. At present, the precise location of the Muling gem de- The crystal hosted several fractures as well as interest- posit source rocks has not been confirmed. According to ing fluid and crystal inclusions. Fractures are very common previous geological studies, the area is localized in the in such thin crystals, causing them to break easily. This northern terminal of the branch of the Tanlu fault (Z. L. specimen broke during the cleaning process (figure 44), and Qiu et al., “Trace element and hafnium isotopes of Ceno- extra care should be taken while handling such crystals. zoic basalt-related zircon megacrysts at Muling, Hei- One inclusion was a flat, opaque, and foliated black crys- longjiang Province, northeast China,” Acta Petrologica tal (possibly graphite) that we could not identify with Raman Sinica, Vol. 23, No. 2, 2007, pp. 481–492). The lava in this spectroscopy. There were also carbonate inclusions (identi- region can be divided into six volcanic eruption cycles; fied as calcite and dolomite using Raman spectroscopy). The Muling has experienced three such cycles (Sun et al., 2005). most fascinating features were the multiphase inclusions; at Based on mining and geological information and our least eight were located in the center of the specimen (figure analysis of Muling rubies and sapphires, we inferred that 45). They were composed of a negative crystal filled with col- this material might have originated as xenocrysts from an orless liquid, hosting a flattened or spherical bubble, filled earlier volcanic eruption and undergone subsequent high- with a liquid and a gas. This was unlike the features in spinel pressure geological processes. These are likely non-classic from Man Sin, where negative crystals are filled with an or- alkali basalt deposits. Large corundum deposits exist from ange liquid rich in sulfur (again, see Pardieu, 2014). eastern China to Primorye in far eastern Russia (I. Graham We assumed that the gas inclusions were mainly CO , 2 et al., “Advances in our understanding of the gem corun- as some of the small bubbles disappeared while the stone dum deposits of the West Pacific continental margins in- was under the microscope and gently heated by the well traplate basaltic fields,” Ore Geology Reviews, Vol. 34, pp. light. This could not be confirmed by Raman analysis; the 200–215), but exact locations have not been confirmed. CO concentration in the solution may have been too low. 2 Although Muling’s corundum deposit have yet to be FTIR spectroscopy confirmed the presence of carbonates mined commercially, the existing production has drawn and oil in some fractures. This might be explained by the the attention of Chinese gemologists and gem dealers. The production may rival that from other high-quality deposits, and this source holds great promise for the future. Figure 43. This 12-sided crystal recently obtained in Yimiao Liu and Ren Lu Mogok is a rare spinel macle, hosting fascinating mul- Gemmological Institute, China University of Geosciences tiphase (liquid + gas) inclusions. The stone is report- Wuhan, China edly from the eastern part of the Mogok Valley. Photo by Victoria Raynaud/GIA; field of view 5.7 mm. “Star of David” spinel twin crystal with multiphase inclu- sions from Mogok. In December 2015, author VP obtained from the Mogok gem market a remarkable spinel crystal with a fascinating Star of David (figure 43). This unusual pat- tern was formed by two triangles on opposing sides of a cen- tral 12-sided polygon. Furthermore, the specimen hosted some conspicuous crystals that resembled fluid inclusions, which are rare in spinel. The stone was reportedly mined in the early 2000s near Pein Pyit, a village in eastern Mogok that is famous for such twinned spinel crystals (T. Themelis, Gems & Mines of Mogok, published by the author, Bangkok, 2008). Hundreds were found in the Mogok market between 2002 and 2004, but most were tiny or broken (V. Pardieu, “Hunting for ‘Jedi’ spinels in Mogok,” Spring 2014 G&G,

100 GEM NEWS INTERNATIONAL GEMS & GEMOLOGY SPRING 2016 Figure 44. The Star of David spinel hosts some interest- Figure 45. About five multiphase inclusions associated ing multiphase inclusions. Such fractured, thin crystals with colorless carbonate crystal are seen in the are very brittle; this one was damaged during the spinel’s center, shown using diffused brightfield illu- cleaning process. Photo by Sasithorn Engniwat/GIA. mination. Photo by Victoria Raynaud/GIA; field of view 2.40 mm. common practice (in Mogok) of keeping crystals in oil before selling them. We also studied the sample using photolumi- monds from New Diamond Technology,” Fall 2015 G&G, nescence and UV-Vis spectroscopy. The Cr3+ band in the PL pp. 260–279). Here we report on large diamond crystals spectra was approximately 0.89 nm wide. In the UV-Vis manufactured using a similar technology by Jinan spectra, there was a clear absorption in the green around 537 Zhongwu New Materials Co. Ltd in Shandong, China. nm. These features confirmed the absence of treatment (S. We visited the Chinese factory in early March 2016 and Saeseaw et al., “Distinguishing heated from unheated obtained 50 crystals (figure 46). The crystals were examined spinel,” GIA News from Research, 2009, www.gia.edu/ using the instrumentation and techniques applied to all di- ongoing-research/distinguishing-heated-unheated-spinel). amonds submitted to GIA for grading; all exhibited the typ- The sample was analyzed using LA-ICP-MS. Three ical characteristics of HPHT growth and were identified as spots were studied and compared to GIA reference data ob- synthetic. These were basically colorless, with only a few tained on other red spinels from different origins. The main metallic inclusions observed. These crystals showed typical trace elements observed were V, Cr, and Zn. Other ele- cuboctahedral morphology, with well-developed {100}, {110}, ments (Li, Be, Ti, Mn, Fe, Co, Ni, and Ga) were also de- and {111} growth sectors and a weakly developed {113} sec- tected in lower but still significant concentrations. Based tor. The crystals we obtained ranged from about 0.5 to 1.2 on GIA’s reference data for origin determination, we would ct each. Absorption spectra in the infrared region showed have identified these as Burmese, with other localities they were type IIa diamond, but trace absorption from boron (Tanzania, Vietnam, or Tajikistan) excluded due to the el- was detected (2800 cm–1). Detailed gemological and spectro- evated Zn and Ni content. Star of David spinels are rare crystals that fascinate many gemologists and collectors. Studying these macles Figure 46. A factory in Shandong, China, is producing promotes our understanding of them and will contribute a large number of colorless HPHT synthetic dia- to origin determination for red spinel. monds for the jewelry industry. These crystals have Vincent Pardieu, Supharart Sangsawong, typical cuboctahedral morphology and weigh up to Wim Vertriest, and Victoria Raynaud 3.5 ct. Photo by Jian Xin (Jae) Liao.

SYNTHETICS AND SIMULANTS

Large colorless HPHT synthetic gem diamonds from China. High-pressure, high-temperature (HPHT) technol- ogy for gem diamond synthesis has made rapid progress in the last few years. It is now being used to produce many melee-size diamonds around 2–3 mm in diameter and large colorless single crystals, all with significantly improved quality and growth rate. One Russian company is report- edly growing multiple large, gem-quality colorless dia- mond crystals in a single run (U.F.S. D’Haenens-Johansson et al., “Large colorless HPHT-grown synthetic gem dia-

GEM NEWS INTERNATIONAL GEMS & GEMOLOGY SPRING 2016 101 scopic analyses are ongoing and will be reported separately. According to the manufacturer, large quantities of gem- quality colorless and blue diamonds are produced in this fac- tory, in sizes up to 3.5 ct each. While the total production volume remains unclear, it is undoubtedly significant, and capacity is likely to expand in the near future. This strongly suggests that even more large HPHT synthetic diamonds will be introduced into the jewelry industry. Wuyi Wang and Tom Moses GIA, New York

TREATMENTS Figure 48. Fractures of the cut samples display thick and cloudy patches, suggesting uneven filling. Pho- Polymer-treated hessonite. Early in 2016, gem merchant tomicrograph by Gagan Choudhary; image width Abdul Hafiz (Jaipur, India) showed this contributor a parcel 6.35 mm. of orangy brown rough hessonite he had purchased, said to be “glass-filled” hessonite. Upon initial observation, the specimens appeared to be treated, as individual crystals were stuck together (figure 47). This is commonly seen in glass- consistent with garnet, specifically hessonite and filled corundum rough; however, the typical glassy surface tsavorite, according to the laboratory’s database. was absent. Rather, the surface appeared greasy, as if it was To check for a polymer filler and record gemological heavily oiled. Since the crystals were stuck together, it was properties, two specimens were faceted, weighing 5.35 and obvious that some more stable form of treatment has been 5.31 ct, respectively (again, see figure 47). Both specimens performed. Further testing was conducted to identify the gave an RI of 1.745 and a hydrostatic SG of 3.60, within the treatment. range for hessonite (M. O’Donoghue, Gems: Their Sources, Under 10× magnification, the joints and cavities showed Descriptions and Identification, 6th ed. Butterworth- a concentration of a foreign substance that was readily in- Heinemann, London, 2006). Both displayed a strong roiled dented with a metal pin, ruling out the presence of glass. or “heat wave” effect and numerous transparent rounded Because of the unpolished surface, we could not see the to elongated colorless crystals, features consistent with hes- filler, but the stone was transparent enough for infrared sonite. The stones had obvious fractures visible to the un- spectroscopy. The spectra showed strong features at approx- aided eye. When magnified, these fractures displayed thick imately 3060, 3032, 2923, and 2871 cm–1; these peaks are and cloudy patches (figure 48), suggesting that a foreign sub- associated with polymer. Other absorption features were stance was used to create an uneven filling. None of the iri- descence or color flashes typically associated with a filled fracture were visible. Both faceted stones also displayed characteristic polymer-related peaks in IR spectroscopy. Figure 47. These three rough hessonite samples (17.92 This was our first encounter with a polymer-treated grams total) are joined by a polymer, which is also hessonite. Because the fractures were eye-visible, it is un- found in surface cavities and joints. The treatment is clear how much value the treatment adds to these low- evident from the rough’s “oily” look. Also note the grade stones. According to Mr. Hafiz, the treatment is visibility of fractures in the 5.31 ct (left) and 5.35 ct performed to stabilize the rough for cutting and polishing; (right) cut samples. Photo by Gagan Choudhary. otherwise the highly fractured material crumbles while processing. He added that hundreds of kilograms of such rough (reportedly African) have been sent to China for treatment. Gagan Choudhary ([email protected]) Gem Testing Laboratory, Jaipur, India

ERRATUM

In the Winter 2015 GNI entry on grandidierite from Mada- gascar (pp. 449–450), the color of the sample was incorrectly presented in figure 4. Please go to www.gia.edu/gems- gemology/winter-2015-gemnews-grandidierite-madagascar to see its actual color.

102 GEM NEWS INTERNATIONAL GEMS & GEMOLOGY SPRING 2016